Breaker core



FIG. 1 is a bottom perspective view of my new design;

FIG. 2 is a top perspective view thereof;

FIG. 3 is a front elevation view thereof, the rear elevation view being identical to the front view;

FIG. 4 is a right side view thereof;

FIG. 5 is a bottom plan view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a side cross-sectional view, taken across the line shown in FIG. 5. 

CLAIM The ornamental design for a breaker core, as shown and described. 